Study ID | Sample size (patients/eyes) | Mean age/ range (years) | Mean duration of diabetes/range (years) | Digital imaging technique | Image resolution (pixels) | Compression rate |
---|---|---|---|---|---|---|
Bursell et al33 | 54/108 | 48/20–75 | 17.7/3.0–42 | 3-field, 45°, stereoscopic, colour, non-mydriatic | 640×480 | 10:1 |
Fransen et al29 | 290/549 | ND/>18 | Any duration | 7-field, 30°, stereoscopic, colour, mydriatic | 1152×1152 | |
Lin et al16 | 197/- | ND/>21 | Any duration | 1-field, 45°, monoscopic, monochromatic, non-mydriatic | 640×480 | |
Massin et al35 | 74/147 | 52/25–74 | 8/0–23 | 5-field, 45°, non-stereoscopic, colour, non-mydriatic | 800×600 | |
Boucher et al27 | 98/196 | 59.9/26–92 | ND | 2-field, 45°, stereoscopic, colour, non-mydriatic | 600×800 | |
Hansen et al20 | 83/165 | 47/25–70 | 22/1–53 | 5-field, 45°, non-stereoscopic, colour, mydriatic | 1450×1026 | |
59/118 | 47/25–70 | 22/1–53 | 5-field, 45°, non-stereoscopic, colour, non-mydriatic | 1450×1026 | ||
Schiffman et al30 | 111/222 | 57/18–99 | 19/1–49 | 15-field, 55–60°, non-stereoscopic, monochromatic, mydriatic | ND | |
Rudnisky et al19 | 102/204 | ND/23–92 | ND/1 months- 35 years | 7-field, 30°, stereoscopic (fields 1 and 2) and non-stereoscopic (fields 3 to fields 7), colour, mydriatic | 3040×2008 | 16:1 |
Li et al23 | 85/152 | 59.4/33–83 | ND | 7-field, 35°, stereoscopic, colour, mydriatic | 2392×2048 | |
Li et al22† | 85/152 | 59.4/33–83 | ND | 7-field, 35°, monoscopic, colour, mydriatic | 2400×2000 | |
Li et al24† | 85/152 | 59.4/33–83 | ND | 7-field, 35°, stereoscopic, colour, mydriatic | 2400×2000 | 37:1 |
Li et al21 | 85/152 | 59.4/33–83 | ND | 7-field, 35°, stereoscopic, colour, mydriatic | 2400×2000 | |
7-field, 35°, stereoscopic, colour, mydriatic | 2400×2000 | 37:1 | ||||
7-field, 35°, monoscopic, colour, mydriatic | 2400×2000 | |||||
9-field, 45°, monoscopic, MosD (mosaic digital), colour, mydriatic | 3000×2000 | |||||
Li et al25† | 85/152 | 59.4/33–83 | ND | 9-field, 45°, monoscopic, MosD, colour, mydriatic | 3000×2000 | |
Gangaputra et al36 | 96/157 | 62/37–86 | 19/ND | 7-field, 30°, stereoscopic or 4-field 45–60° stereoscopic, colour, mydriatic* | ND | |
Hubbard et al15 | 319/628 | 48/ND | 27.2/ND | 7-field, 30°, stereoscopic, colour, mydriatic | ND | 20:1 |
Kernt et al17 | 34/66 | 62/ND | 14.2/>3 | 1-field, 200°, non-stereoscopic, colour, non-mydriatic | ND | |
Maker et al26 | 106/211 | 49/19–78 | 23.7/1–66 | 7-field, 30°, stereoscopic, colour, mydriatic | 1280×1024 | |
Silva et al31 | 67/126 | 49/24–83 | 21.1/1–51 | 3 separate stereoscopic 45° fields, 2 30° stereoscopic fields, and an external image, colour, non-mydriatic | 1000×1000 | |
Silva et al32 | 103/206 | 53.9/18–88 | ND | 1-field, 100° and 200°, stereoscopic, colour, non-mydriatic | 1200×1600 | |
Kernt et al18 | 141/212 | 64/25–78 | 12/3–39 | 1-field, 180–200°, non-stereoscopic, colour, non-mydriatic | 3900×3072 |
*48 (31%) digital images were obtained at a 45–60° angle and 109 (69%) with the common 30° angle.
†There were three comparable groups in the three studies: two of these groups were identical. One used the reference standard 7F-ETDRS; the other involved 7-field 35° stereoscopic colour images with mydriasis. The third comparable group differed from those in the three studies and is presented in the table.
ETDRS, Early Treatment Diabetic Retinopathy Study; ND, no data available.